There are two main styles of defensemen, them being stay-at-home defensemen and offensive defensemen.
Those players prefer staying in their own zone. They don't score much, since they prefer to focus on their defensive duties, but rarely get caught off-position on the ice by incoming opponents. A good exemple of stay-at-home defensemen is Brad Marsh.
As the name indicates, offensive defensemen like to support the offensive, often leaving their own zone to go in the opponent's. Defensemen playing this style do score much more often than stay-at-home defensemen, but this come at a price: they risk more to be caught off-position while they support the attack, which can lead to breakaways for the opposite team. Some of the best even managed to win the NHL's scoring title, or even reach the 100 points plateau in a season. Some of the best players who have played this style are Bobby Orr, Paul Coffey and Raymond Bourque.